Cortisol, which I have bloggedaboutbefore, is a major endocrine involved in the human stress response (corticosterone, a closely-related steroid, serves the same purpose in many other animals). Stressful experiences are also learning experiences for many individuals ("I'll never do that again..." etc.), and cortisol seems to have an impact on the building and retrieval of memories. Specifically, it appears to promote the storage of new memories while simultaneously repressing the retrieval of already stored memories. This makes it a potentially beneficial supplement during exposure therapy, which is based on replacing traumatic memories of objects, events, or situations with repeated non-traumatic exposures to "unlearn" the fear.

In this study, the authors compared two groups of people undergoing exposure therapy for their fear of heights: a control group that received a placebo and an experimental group that received 20mg of cortisol one hour before their treatment sessions. (The two groups did not differ in baseline levels of cortisol, and the experimental group did have higher levels of circulating cortisol, both validated by saliva samples.)

Exposure therapy reduced self-reported fear in both groups, but the effect was amplified in the cortisol group, both 3-5 days after treatment and at follow-up a month later. This suggests that cortisol supplementation increases the efficacy of exposure therapy in people who have specific phobias of heights. However, more studies need to be done to see if the cortisol treatment has continuing long-term effects in the fear response.

I hesitate to jump for joy because I have no idea if exposure therapy (with or without cortisol) would be effective or even possible for my specific phobia. I am not sure how well these results can be extrapolated to other specific phobias, although previous research suggests it may also be beneficial in arachnophobia and social phobia.

1 comment:

I don't find this all that surprising. Exposure therapy relies on raising arousal level, and the researchers did that artificially doing that with cortisol. They should have had two different independent variables: a low height vs. high height (relatively speaking) and active cortisol vs. placebo, and seen what the interaction looked like. I bet the high height placebo would be awfully close to the low height cortisol.

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C6H12O6 is the molecular formula for glucose. Glucose is a monosaccharide that plays a major role in energy production via cell metabolism. Glucose is delicious and sweet, and you need it to surivive, but too much glucose can make you obese and give you Type II diabetes. I picked it as the namesake for my blog because metabolic rate is the cornerstone of my field, comparative physiology.

I'm Michelle, a newly minted M.Sc. from an ecophysiology lab, and a technical editor for a scientific journal publishing group. Physiologically, I have an overactive sympathetic nervous system. Personally, I am agoraphobic and kind of a nerd. In my free time I blog and drink way too much tea.